Re: The report is not completely accurate
I'm absolutely sure that something like a warship would have electronic countermeasures on board to disrupt things like thermal targeting (such as thermal chaff, for example, but probably a more high-tech equivalent), and GPS. Blowing up a bridge probably has different considerations again; it's one thing to steer an unmanned sea drone to the vicinity of the bridge, and another again to hit the spot you want to (presumably, the targeting points are quite specific as there are unlikely to be many weak points in Putin's armoured bridge), rather than simply continuing under it.
Ukraine are probably working with what they have. Yes, you can do all sorts of fancy things with arduinos or other microcontrollers, but if you want to launch an attack today, you'd be out of luck with the lead-time on the development and testing of the integration of those into any guidance system. I'm sure, as the war progresses, the sea-drone attacks will become more sophisticated (and the evidence is that the Ukrainian home-brew drones are already quite effective). They'll probably be developing and using several variants on designs, as this is a classic arms race between developing weapons and developing defences against those weapons. Ukraine will want to keep that as asymmetric as possible, as they are fighting the larger, less agile, enemy.